Lens grinding machine



1934- J. E. MARSHALL LENS GRINDING MACHINE Filed Nov. 13, 1951 3 SheeCs-Sheet 1 a z?ai z7ey '@cfi.9,1'934. v J. E. MARSHALL I 11,975,834

LENS GRINDING MACHINE Filed Nov. 15, 1 51 3 Sheets-Sheet 2 3 Sheets- Sheet 3 Filed NOV. 13, 1931 I 40 passes. Pinned to the shaft with another bevel gear 21 the shaft 22 is threaded which extends rearwardly 26 in the supporting memi atenteci Oct. 9 1934 My present invention 3 Claims.

relates to lens grinding machines and more particularly to an automatic lens grinding machine.

The principal object of my invention is an improved lens grinding machine;

Another object is an improved automatic lens grinding machine which may be set such that the to receive machine will automatically stop when the amount of grinding has desired been accomplished;

Other objects and novel features comprising the construction and operation of my invention will appear as the description of the same progresses.

Referring to the drawings illustrating the preferred embodiment of my invention;

Fig. 1 shows a side elevation of the complete machine;

Fig. 2 is a rear elevation, and Fig. 3 is a partial cross-section and front elevation indicated at 33 Referring more in det indicates the base of the vertically located a supp of Fig. 1.

ail to the drawings, 10 machine upon which is orting member 11.. At-

tached to the vertical supporting member 11 on its inner side is a slide way and vertically casing 13 carries all the exterior parts of which are;

12 which is adapted guide a casing 13. The driving mechanism the an electrical driven motor 14 attached to one side of the casing 13; a drive shaft 15 vertically mounted within the front portion of the casing 13 tached at its lowermost end and indicated -at Fig. 3; an upper rotatable member 1'7 attached to the upper end of the shaft 15 in which abrasive grinding compound able on the guide having a, pulley 16 atis carried. The entire structure including the motor 14, pulley 16, casing 13, and the container 12 by means of a crank mem- 17 is vertically adjustber 18 which is journalled in the supporting member 11 through 20 adapted to mesh which the crank shaft 19 19 is a bevel gear secured to a vertical shaft 22 journalled within a bearing 23 attached to 11 by means of bolts 24 of the casing 11 through the opening her 11 as indicated at 27. 18 the casing 11 together with the parts may be elevated or all connecting internal the supporting member The lower portion of at 25 through a portion By rotating the crank motor 14 and dropped to any desired amount within the range of the mechanism.

At the top of the upri 11 is located the lens ght supporting member holding and adjusting rice mechanism which comprises a horizontally adjustable bracket member provided at the front portion with a yoke 23 and a horizontal slidable rod portion 29. The rod portion 29 is adapted to be received in an opening provided therefor in the upper portion of the member 11 the front portion of which comprises a with a set screw 31 for the provided on one side purpose of locking the the rod member 29. The rod 29 is further proboss 30 which is horizontal movement of vided witha key member 32provided for the purpose of preventing the rod member 29 from rotating. Clamped to the member 28 are bearing nalled within. the bearing cap between the caps 33 and front front side of the yoke cap members 33. Jourmembers 33 and face of the yoke 28 are trunnions comprising a portion of the lens bearing casing 34.

to pivot on its trunnions scribed for the purpose of adjusting the angle may be desired to grind a lens.

at which it handle 35 is attached to one The casing 34 is adapted in the bearings just de- A of the trunnions 36 for the purpose of easily adjusting the casing 34 and is further provided 37 which is calibrated with a scale 38 inscribed on a plate 39 which is 11. A looking screw 40 with an indicator pointer attached to the member is provided on the opposite side in the cap member 33 such that its inner end bears directly on the adjacent trunnion for the purpose of bearing casing 34 at any desired angle.

Within the cup member member 41 which is fixed 5 such that it rotates with these mem- This tool member 41 shown in the drawand shaft 1 bers. ings illustrates a tool f0 securely locking the lens 17 is located a tool to the cup member 17 r grinding concaved surfaces in lenses and where it is desired that a convexed caved surface is used. fixed to a lens holder surface be ground, a tool having a con- The lens 42 is usually 43 by sealing wax, the

lens holder being recessed to hold a quantity of Y the wax. The holder bearing 43 is held in a rotatable member 44 which is journalled on ball bearings within the casing 34 such that when the tool 41 is rotating and grinding the lens 42 is freely held and self centering.

One of the important improvements in my present invention comprises the automatic vertical adjustment inclosed within the casing 11. In Fig. 3 it will be noted that the shaft 15 is 5 provided with a fixed the bottom side of the casing cover collar 50 directly below plate 51 which also forms one end bearing for the shaft 15, the opposite end being journalled in the bottom of the casing 11 at 52. A pair of ball thrust bearings 53 and 54 are separated by a yoke member 55 comprising a portion or" the lever 56 which is pivoted to a hanger portion of the cover 51 at 58. A third ball thrust bearing 57 is located above the boss 52 and is separated from the hearing 54 by a compression spring 60. The lever 56 is provided with a pointer 61 at its free end and is adapted to register with a graduated scale 65 located on an extension bracket 66 attached to one side to the casing 13 such that the movement of the shaft 15 up or down causes the pointer 61 to register on the scale 65. Inserted in the side of the bracket 66 is a toggle switch 67 adapted to control the motor 14 and operated by means of the lower side of the lever 56.

In operation, a lens is inserted in the holder 43 and the casing 34 is adjusted horizontally to the desired point the angle of casing 34 is then adjusted by means of the scale 39 and pointer 3'7. The casing 13 is now elevated by means of the crank 18 until the pointer 61 registers at the desired point on the scale 65. The motor switch 67 is now opened and the tool ll caused to rotate against the lens 42. The tool 41 is now under a tension exerted thereon from the spring 60 and as. the material comprising the lens is ground away the lever 55 gradually approaches the switch 6'7 until the switch is closed and the motor stopped and the grinding operation completed.

Having thus described my invention what I claim as new, is:

1. A lens grinding machine comprising a base, a vertical supporting member, a lens holding member attached to said supporting member, a casing vertically adjustable on said supporting member, a vertical drive shaft located within said casing, an electrical motor attached to said casing and adapted to drive said shaft, a grinding tool attached to said shaft adapted to be rotated by said shaft, a compression spring located adjacent the inner lower side of said casing and surrounding said shaft and adapted to force said tooi against said lens, a transverse lever located in the side of said casing and pivoted at its central portion to the inner top of said casing, a yoke comprising the inner end of said lever adapted to be moved up or down in a vertical direction with said shaft by means of said compression spring, a switch adapted to be operated by said lever for the purpose of stopping said motor.

2. A lens grinding machine comprising a base, a vertical supporting member, a lens holding bearing member attached to said supporting member, means for adjusting said lens holding bearing member in a horizontal plane and means for adjusting said lens holding member on a pivot at various angles in a vertical plane, a casing vertically adjustable on said supporting member, a vertical drive shaft journalled within said casing, an electrical motor attached to one side of said casing and adapted to drive said shaft, resilient means for holding said shaft in vertical contact with said lens, a lever pivoted within said casing and adapted to be pivoted up or down with said shaft, means associated with said lever adapted to stop said motor at a predetermined point, a grinding tool located on the end of said shaft adapted to grind said lens, substantially as shown and described.

3. A lens grinding machine comprising a base having an upright member located at one side thereon, a rod member horizontally disposed through the top of said upright member and provided with a yoke construction at one end thereof, a lens holding member pivotally attached through said yoke construction and extending downwardly therefrom, a grinding tool housing mounted in the lower portion of said upright member in a vertically adjustable manner, a rotatable grinding tool vertically disposed in said grinding tool housing adapted to be maintained under tension upwardly against a lens located on said lens holder.

JOHN EDWARD MARSHALL.

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